No abstract available.
HMGB1 Protein* ; Pemphigus*

Humans ; Asthma/diagnosis* ; HMGB1 Protein

HMGB1 is a widely existing DNA-binding nuclear protein, participating in gene transcription, damage repair, recombination and stabilizing nucleosome construction. Under injury, infection and chemotherapy, HMGB1 can be released by nature immunocyte and necrosis cells as a DAMP, exerting pleiotropic biological effects by binding to RAGE, TLR and CXCL12, which lead to activation of CDC42, mitogen-activated protein kinases (MAPKs), c-IAP and NF-κB, thereby promoting angiogenesis, unlimited replicative potential, tissue invasion and metastasis. And it also involves in immune response by regulating immunocyte function as a immunocyte warning signal. Scholars have detected that HMGB1 is over expressed and released following chemotherapy and radiation therapy in cells of hematological malignancies, promoting malignant cell replication, decreasing therapeutic effect. Recently, endogenous HMGB1 has been implied to be an intrinsic modulator of autophagy and referenced to resistant to apoptosis in malignant hematosis cells. In contrast, through suppression of HMGB1 expression, tumor cell apoptosis and chemotherapeutic drug sensitivity were increased, which will be a new strategy for the treatment of hematological malignancies. In this article, the basic characteristics of HMGB1, including structure and biological features, and HMGB1 and tumors such as lymphoma, myeloproliferative neoplasms and acute myeloid leukemia are reviewed.
Animals ; HMGB1 Protein ; Hematologic Neoplasms ; therapy ; Humans

Endotoxemia ; metabolism ; pathology ; HMGB1 Protein ; Humans ; Liver ; metabolism ; pathology

High mobility group box-1 protein (HMGB1), which is a nuclear protein, participates in chromatin architecture and transcriptional regulation. When released from cells, HMGB1 also plays a well-established role as a pro-inflammatory mediator during innate immune responses to injury. In the initial stage of injury, there is a release of large quantities of early pro-inflammatory mediators to initiate or perpetuate immune responses against pathogens, but this pro-inflammatory period is transient, and it is followed by a prolonged period of immune suppression. At present, several lines of evidences have suggested that HMGB1 is a late cytokine provoking delayed endotoxin morbidity, which may enhance the production of early proinflammatory mediators, and it can contribute potently to the activation of different immune cells and play a role in the development of host cell-mediated immunity. The biology of HMGB1 has been extensively studied as a pro-inflammatory cytokine of systemic inflammation, however, this review will attempt to provide a summary of the effects of HMGB1 on different immune cells and its regulatory mechanism in acute insults.
Cytokines ; immunology ; HMGB1 Protein ; immunology ; Humans ; Immunity, Cellular ; Inflammation ; immunology

High mobility group box 1 (HMGB1) is an endogenous danger signal molecule. In the postischemic brain, HMGB1 is massively released during NMDA-induced acute damage and triggers inflammatory processes. In a previous study, we demonstrated that intranasally delivered HMGB1 binding heptamer peptide (HBHP; HMSKPVQ) affords robust neuroprotective effects in the ischemic brain after middle cerebral artery occlusion (MCAO, 60 minutes). In the present study, we investigated HBHP-induced anti-inflammatory effects on microglia activation. In LPS-treated primary microglia culture, HMGB1 was rapidly released and accumulated in culture media. Furthermore, LPS-conditioned media collected from primary microglia cultures (LCM) activated naive microglia and markedly induced NO and proinflammatory cytokines. However, the suppression of HMGB1 by siRNA-HMGB1, HMGB1 A box, or anti-HMGB1 antibody significantly attenuated LCM-induced microglial activation, suggesting that HMGB1 plays a critical role in this process. A pull-down assay using biotin-labeled HBHP showed that HBHP binds directly to HMGB1 (more specifically to HMGB1 A box) in LCM. In addition, HBHP consistently inhibited LCM-induced microglial activation and suppressed the inductions of iNOS and proinflammatory cytokines. Together these results suggest that HBHP confers anti-inflammatory effects in activated microglia cultures by forming a complex with HMGB1.
Brain ; Culture Media ; Cytokines ; HMGB1 Protein ; Infarction, Middle Cerebral Artery ; Inflammation ; Microglia* ; Neuroprotective Agents

Eosinophils have been reported to modulate T cell responses. Previously, we reported that high-mobility group box 1 protein (HMGB1) played a key role in the pathogenesis of asthma. This study was conducted to test our hypothesis that eosinophils could modulate T cell responses via HMGB1 in the pathogenesis of asthma characterized by eosinophilic airway inflammation. We performed in vitro experiments using eosinophils, dendritic cells (DCs), and CD4+ T cells obtained from a murine model of asthma. The supernatant of the eosinophil culture was found to significantly increase the levels of interleukin (IL)-4 and IL-5 in the supernatant of CD4+ T cells co-cultured with DCs. HMGB1 levels increased in the supernatant of the eosinophil culture stimulated with IL-5. Anti-HMGB1 antibodies significantly attenuated increases of IL-4 and IL-5 levels in the supernatant of CD4+ T cells co-cultured with DCs that were induced by the supernatant of the eosinophil culture. In addition, anti-HMGB1 antibodies significantly attenuated the expressions of activation markers (CD44 and CD69) on CD4+ T cells. Our data suggest that eosinophils modulate CD4+ T cell responses via HMGB1 in the pathogenesis of asthma.
Antibodies ; Asthma* ; Dendritic Cells ; Eosinophils* ; HMGB1 Protein ; Inflammation ; Interleukin-4 ; Interleukin-5 ; Interleukins ; T-Lymphocytes

Atrial fibrillation (AF) is the most common sustained dysrhythmia in clinical practice. The bulk of evidence suggests that inflammatory processes, oxidative stress and matrix metalloproteinase are associated with development of AF. However, these agents may be involved in high mobility group box 1 protein (HMGB1). We hypothesized that HMGB1 may be a possible pathogenic link to AF. A growing body of evidence supports these hypotheses. First, the level of serum HMGB1 is significantly increased in patients with AF including paroxysmal and persistent AF. Second, HMGB1 has been identified as a new pro-inflammatory cytokine in cardiovascular diseases, along with tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C-reactive protein, and there is cross-talk between HMGB1 and inflammatory cytokines. Third, oxidative stress is involved in the release of the pro-inflammatory cytokine, HMGB1, indicating there is cross-talk between oxidative stress and inflammation, and oxidative stress may reinforce the effect of inflammation on the pathogenesis of AF and inflammation may play a more important role in the pathogenesis of AF. Fourth, HMGB1 can promote matrix metalloproteinase-9 upregulation and activation. Fifth, HMGB1 receptors (receptor for advanced glycation end products, Toll-like receptor-2,4) may mediate the atrial structural remodeling or be up-regulated in patients with non-valvular AF. These results suggest that HMGB1 may participate in the pathogenesis of AF and provide a potential target for pharmacological interruption of AF.
Atrial Fibrillation ; metabolism ; HMGB1 Protein ; metabolism ; Humans ; Metalloendopeptidases ; metabolism ; Oxidative Stress ; physiology

OBJECTIVETo investigate the significance of changes in plasma high mobility group box-1 protein (HMGB1) levels and its relationship with sepsis and endotojemia in severely burned patients.

METHODSTotally 25 large area burned patients ( > 30% total body surface area) were included in this study, and 8 healthy volunteers served as normal controls. The plasma levels of HMGB1 were measured by ELISA, and endotoxin concentrations was determined by the modified chromogenic limulus amebocyte lysate (LAL) assay on posthurn days 1, 3, 5, 7, 14, 21, and 28.

RESULTSThe plasma HMGBL levels were markedly elevated on postburn day 1 in severely burned patients, and they were significantly higher in septic patients than those without sepsis on days 7, 21, and 28 after burns (P<0.05). Among septic patients, plasma HMGBI levels in the survival group were significantly lower than those with fatal outcome on days 3 and 21 (P<0.05, P<0.01). No significant correlations were found between HMGB1 levels and the sizes of total body surface area (P>0.05). In addition, the plasma HMGB1 levels were positively correlated with endotoxin concentrations on days 3, 5, 7, 21 after major burns (P<0.05, P<0.01).

CONCLUSIONSHMGB1, as an important late mediators of inflammation, may be involved in the development of sepsis following extensive burns, and it can be markedly induced by endotoxemia secondary to acute insults. Dynamic measurements of circulating HMGB1 levels should be helpful to monitor the disease course and judge the prognosis of burned patients.

Burns ; blood ; microbiology ; Endotoxins ; blood ; HMGB1 Protein ; blood ; Humans ; Sepsis ; blood

OBJECTIVETo investigate the expression of high mobility group box 1 (HMGB1) in gingival tissues of chronic periodontitis.

METHODSHuman peripheral blood mononuclear cells(PBMC) were stimulated with 1 microg x mL(-1) lipopolysaccharide (LPS) for 24 h or 48 h. Expression and release of HMGB1 were checked by immunofluorescence and enzyme-linked immunosorbent assay (ELISA), respectively. PBMC were stimulated with 100 ng x mL(-1) HMGB1 or 50 ng x mL(-1) tumor necrosis factor-alpha (TNF-alpha), the expressions of TNF-alpha and HMGB1 in the supernatant were studied by ELISA. Gingival tissues and gingival crevicular fluids (GCF) were collected from patients and healthy people. Expression of HMGB1 in gingival tissues and GCF was studied using immunofluorescence and ELISA, respectively.

RESULTSHMGB1 was translocated from nucleus to cytosol in PBMC after LPS stimulation for 24 h. The content of HMGB1 in the supernatant from stimulated cells was significantly higher than that from unstimulated cells after 48 h (P < 0.01). HMGB1 was released by PBMC in response to TNF-alpha stimulation, it also stimulated PBMC to release TNF-alpha (P < 0.01). Translocation of HMGB1 from nucleus to cytosol was also found in infiltrated cells in gingival tissues from patients, and HMGB1 in GCF from patients was significantly higher than that from healthy people P < 0.01).

CONCLUSIONThe results suggest that HMGB1 may play an important role in the pathological progress of chronic periodontitis.

Chronic Periodontitis ; Gingiva ; HMGB1 Protein ; Humans ; Leukocytes, Mononuclear ; Male ; Tumor Necrosis Factor-alpha